Acne is the most common cutaneous disorder of multi-factorial origin with a prevalence of 70-85% in adolescents. According to the statistics, nearly 85% of people aged 12-25 years, approximately 8% of adults aged 25-34 years, and 3% of adults aged 35-44 years experience some degree of acne [Befd W F, J Am Acad Dermatol 1995; 32:552-556]. In the US alone, between 40 and 50 million people are estimated to be affected by some form of acne, with approximately 17 million having clinical acne [Thiboutot D, Arch Fam Med; 2000; 9:179-187]. Although acne and other skin disorders such as eczema, psoriasis, aging, scaring and the like are not life-threatening diseases, but it has significant physical and psychological ramifications such as permanent scarring, poor self-image, social inhibition, depression, anxiety and suicidal tendency [Gupta et al, Br J Dermattol; 1998; 78:451-456]. Therefore, these may be regarded as serious medical disorders. Moreover, there is increasing evidence that hereditary factors and stress play an important but indirect role in acne and the said skin orders. Recently, smoking have also been found to be associated with these diseases. Topical therapy is inevitable in acne treatment and is mainly indicated in the mild to moderate acne. In more severe forms, a combined topical and systemic therapy is recommended [Date Et al, Skin Pharmacol Physiol; 2006; 19:2-16].
The available topical agents have a direct or indirect influence on the patho-genetic factors and are selected according to the predominant type of acne lesions. The therapeutic success in acne and related skin disorders are highly dependent on a regular application of the topical agents over a prolonged period of time. However, disadvantages associated with the commonly used topical agents considerably affect the patient compliance and obstruct the treatment. Currently, available treatment for acne and related skin disorders is mostly based on antibiotics and retinoids. The uses of antibiotics have a lot of limitations due to development of resistance by bacteria. Retinoids are highly teratogenic.
Most of the anti-acne agents are virtually insoluble in water, and thus difficult to incorporate into aqueous systems. Thus the strategy of combining many anti-acne actives in one composition to treat acne is not new, for example, such a combination is disclosed in U.S. Pat. No. 5,976,565 as a patch. Another combination is described in U.S. Pat. No. 4,428,933, wherein a combination of oats, sulfur powder, zinc gluconate, mustard seed, boric acid powder, brewer's yeast, hydrogen peroxide, iso-propyl alcohol, water, methyl p. hydroxy benzoate, and egg yolks are described for treating acne. Patent WO/2003/030816 discuss about anti acne formulation derived from natural products particularly poly-sacchrides from red algae.
The use of salicylic acid in the treatment of common or teen acne is known. For example, U.S. Pat. No. 4,665,063 describes the use of topically applied aspirin (acetyl salicylic acid) for treating common acne; and U.S. Pat. No. 4,891,227 describes the use of pads for applying anti-acne products containing salicylic acid for oily skin. These patents describe state-of-art compositions which emphasize aggressive chemical and physical treatment suitable for teen acne, without addressing the suitability for adult acne and/or the need for mildness.
U.S. Pat. No. 4,800,197 describes a combination of salicylic acid and an anionic taurate surfactant, specifically sodium methyl cocoyl taurate or sodium methyl oleoyl taurate. U.S. Pat. No. 5,296,476 describes the specific use of salicylic acid in combination with calcium citrate. Again, these treatment modalities are designed for aggressive, physical cleansing, which assumes that the individual indicators are normal, young and oily skin.
Currently available forms of salicylic acid tend to aggravate the relatively dry adult acne, and they are particularly unsuitable for those with sensitive skin conditions such as irritant folliculitis. Known salicylic acid preparations are also poorly tolerated in patients suffering from acne complexed with rosacea.
Therefore, an alternative treatment for acne and other skin disorders must be studied and developed. This creates a great interest towards the possible effect of natural substances on antibacterial, anti-inflammatory, oxidative stress reducing action in these diseases. Novel drug delivery strategies have also been instrumental in optimizing efficacy of therapeutic agents by either modulating their physico-chemical and bio-pharmaceutical properties or minimizing/eliminating the side effects associated with them, reducing treatment time thus offering better patient compliance.
This is well documented in prior art that essential oils are valuable tool for skin care. Essential oils plays an very important role in acne treatment because they are soluble through lipids in the skin and are easily absorbed and also because of their ability to dissolve sebum, kill bacteria, and preserve the acid mantle of the skin. Used full strength or diluted with a carrier oil, essential oils can be applied topically to relieve mild to moderate acne. Some essential oils commonly used for acne treatment are Rosewood Oil, Jojoba Oil, Bergamot Oil, Clove Oil, Lavender Oil, Tea Tree Oil, Tulsi oil, Rosemary oil, Lavender oil, Mentha oil etc.
Tea tree oil is an excellent antibacterial treatment making it an excellent acne fighter as well as a general purpose wound cleaner. Biju et al. [Pharmazie 2005; 60: 208-211] have developed micro-emulsions using tea tree oil, using isopropyl myristate, Polysorbate 80, glycerin with water and U.S. Pat. No. 6,464,989 B2 discloses tea tree oil emulsion but not with aqueous phase using rose water and lemon juice as therapeutic agents entrapped in oil phase of one or more essential oils as used in the current invention.
Irritant folliculitis, caused by epithelial irritations, is another sensitive skin condition which manifests as erythematous papules and follicular pustules. Recurrent episodes of irritant folliculitis are sometimes misdiagnosed as common acne and treated with physical abrasives and exfoliants which traumatize and aggravate the original condition.
Acne is the most common cutaneous disorder of multi-factorial origin with a prevalence of 70-85% in adolescents. According to the statistics, nearly 85% of people aged 12-25 years, approximately 8% of adults aged 25-34 years, and 3% of adults aged 35-44 years experience some degree of acne. Therefore, these may be regarded as a serious medical disorders and need an improved solution. Therefore, there is a dire need to develop such formulations which are effective to all skin types and have synergistic multiple effects, have good penetration, long acting to avoid repeated administration, non irritating and involves both aqueous and lipid phases in specific ratio to provide a cure for skin treatments to minimize the adverse effects and maximize the efficacy.